import React, { Component } from 'react';

//引入store，用于获取redux中的状态
import store from '../../redux/store';

//引入actionCreator，专门用于创建action对象
import { createIncrementAction, createDecrementAction } from '../../redux/count_action'


export default class Count extends Component {

    state = { carName: '奔驰c63' }

    // componentDidMount() {
    //     // 检测redux中状态的变化，只要变化，就调用render
    //     store.subscribe(() => {
    //         this.setState({});
    //     })

    // }

    //加法
    increment = () => {
        const { value } = this.selectNumber;
        store.dispatch(createIncrementAction(parseInt(value)));
    }


    //减法
    decrement = () => {
        const { value } = this.selectNumber;
        store.dispatch(createDecrementAction(parseInt(value)));

    }

    //奇数再加
    incrementIfOdd = () => {
        const { value } = this.selectNumber;
        const count = store.getState();
        if (count % 2 !== 0) store.dispatch(createIncrementAction(parseInt(value)));
    }

    incrementAsnyc = () => {
        const { value } = this.selectNumber;
        setTimeout(() => { store.dispatch(createIncrementAction(parseInt(value))) }, 500);
    }

    render() {
        return (
            <div>
                <h1>当前求和为: {store.getState()}</h1>
                <select ref={c => this.selectNumber = c}>
                    <option value='1'>1</option>
                    <option value='2'>2</option>
                    <option value='3'>3</option>

                </select>&nbsp;
                <button onClick={this.increment}>+</button>
                <button onClick={this.decrement}>-</button>
                <button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>
                <button onClick={this.incrementAsnyc}>异步加</button>
            </div>
        )
    }
}
